The first lesula found was a young captive animal seen in 2007 in a school director’s compound in the town of Opala in the Democratic Republic of Congo. The young monkey bore a resemblance to the owl faced monkey, but its coloration was unlike that of any other known species. Over the following three years, the study authors located additional lesula in the wild, determined its genetic and anatomical distinctiveness, and made initial observations of its behavior and ecology, as reported in the PLOS ONE paper.

The new species’ range covers about 6,500 square miles in central DRC, in what was one of Congo’s last biologically unexplored forest blocks. Although its range is remote and only lightly settled at present, the lesula is threatened by local bush meat hunting. “The challenge for conservation now in Congo is to intervene before losses become definitive,” say John and Terese Hart, who led the project. “Species with small ranges like the lesula can move from vulnerable to seriously endangered over the course of just a few years.”